Features: This Photo filter set is compatible with all 77mm lenses. This ND filters set come in ND2, ND4, ND8 different levels. Apply slow shutter speed under strong sunlight exposure, large aperture is available to create depth of field easily. These filters are double threaded allowing additional filters or accessories to be mounted one over the other. Made of high quality optical materials. The number indicates the fraction by which light is reduced; for example, ND2 cuts the light entering the lens by 1/2, ND4 by 1/4, and ND8 by 1/8. Filters are packed in carry pouches with 3 pockets respectively. Specifications: Material of filter: Optical resin Back thread diameter (attach to lens, male thread): 77mm Front thread diameter (attach additional filter, female thread): 77mm Package size: 10.2 * 11 * 3cm / 4.0 * 4.3 * 1.2in Package weight: 89g / 3.15oz Package List: 3 * ND Filter(ND2+ND4+ND8) 1 * Carrying Pouch